Bicycle Mechanics - Cassette, 7-sp 8-sp, 126mm 130mm???

Help.

I am looking at getting a new (used= new to me) set of wheels for my bike.
The price is right, they look good, and It seems like they WILL hold my butt up pretty reliably. The problem is...
They are equipped with 8-9 speed compatible Ultegra hubs. My bike is currently equipped with RX-100 hubs w/ a 7-speed, hyperglide cassette (12-28). It IS a cassette and not a freewheel, which a few people have asked since I've been wheel shopping. I read up on the things @ Sheldon Brown's, and I think I'm more confused now than I was before.
I think my concerns are...
1) Will my 7-speed cassette fit onto the 8-9 hubs?
1a) if not, then can I buy a newer cassette that WILL work without having to upgrade the entire drivetrain?
1b) If not, what CAN I do to put new wheels at the least cost?
2) Frame spacing. Sheldon says that 7-speeds ususlly have 126mm spacing and 8-9 speeds are @130mm. I measured between the inside faces of the dropouts. 5-1/16 inches. Arrgh, which size is it? 126 or 130? 128???

Any help?

Yes, a 7sp cassette will work on an 8-9 sp freehub. You just need to put on a spacer before putting on the cassette to make up for the difference in width. The spacers are inexpensive.

If your frame is steel you don't really need to do anything about the spacing. You can just spread the dropouts a bit as you put wheels on. 4 mm is just over 1/8". It doesn't take much. I do this with an old 6 sp Bianchi that I am now running 9sp cassettes on. If the frame is aluminum or carbon stick with the current spacing. You can buy a 7sp freehub body and shorter axle to replace the 8-9 and keep the spacing the same. Talk to your lbs or call Harris Cyclery and tell them what you are doing. They have what you need whether it is the spacer or new freehub and axle whichever you decide on. If your frame is steel go ahead and use the 8-9 body and spacer since that will be the least expensive option.

I have been through this both ways. Feel free to ask for more info if you need it.
Regards,
Raymond

Very timely as my new 8-9 sp wheels are 130 spacing, and my frame (531c) is 126.

However, I just cannot spread it enough to comfortably get the rear wheel on. I've just had a repaint and don't want to ruin the finish. Also having a struggle to put the wheel on in the comfort of my garage is one thing, taking it off in the cold to repair a puncture outside is another. I think I'm not as muscular as you Rainman :)

i read the article on Sheldon Brown's website on cold setting and thought about doing it myself, but then decided to 'phone some bike shops.

I also contacted M Steel in Newcastle, which would involve a raiding trip over the border.

I've found a frame builder who will cold set the frame for £10 ($16), on a hand in one day ready the next. There is still a risk that the frame won't take to kindly to it (I think the brake bridge is the source of worry on some bikes) but as mine is handbuilt it should be ok.

Worth phoning round.

Any good LBS will have the correct tool to spread the spacing on a steel bike and keep the faces of the dropouts parallel. I ride older steel frames and have had all successfully spread with no problems. I believe that Ti can also be spread, but check with the manufacturer. All other frame materials are set and should not be widened by your LBS. This process generally takes about 15 minutes, if you bring in the frame with the wheel and RD removed. Very simple and straight-forward process. If performed correctly it will also align your frameset so that the wheels both track in the same line. Then add the spacer to your 7-speed cassette, reset the shifting on the derailleur and your are riding again. Believe all of this is quite well documented in Lennard Zinn's road bike maintenance manual. A most excellent tome. Have fun!

Originally posted by chewa


However, I just cannot spread it enough to comfortably get the rear wheel on. I've just had a repaint and don't want to ruin the finish. Also having a struggle to put the wheel on in the comfort of my garage is one thing, taking it off in the cold to repair a puncture outside is another. I think I'm not as muscular as you Rainman :)

Check the new hubs.Often thinner locknuts can be substituted that will make the job a bit easier.

Pokey is correct about the locknuts-- I've respaced hubs on occasion instead of going thru the cold set process, shortening the OLD (over locknut dimension) of the hubs.
If you're doing any work on your bike, I recommend buying a set of metric dial calipers. They sell for about twenty-five bucks on ebay. The calipers will save you a lot of hassles when figuring spacing and lengths of things.

Look at Precision pedal's response:
http://bikeforums.net/showthread.php?postid=155629#post155629

Originally posted by pokey
Check the new hubs.Often thinner locknuts can be substituted that will make the job a bit easier.

Thought about that, but the hubs are Hope hubs which are top of the range and v expensive ($140 for the rear) and use cartridge bearings, so don't have locknuts as such.

Yes, a 7sp cassette will work on an 8-9 sp freehub. You just need to put on a spacer before putting on the cassette to make up for the difference in width. The spacers are inexpensive.

If your frame is steel you don't really need to do anything about the spacing. You can just spread the dropouts a bit as you put wheels on. 4 mm is just over 1/8". It doesn't take much. I do this with an old 6 sp Bianchi that I am now running 9sp cassettes on. If the frame is aluminum or carbon stick with the current spacing. You can buy a 7sp freehub body and shorter axle to replace the 8-9 and keep the spacing the same. Talk to your lbs or call Harris Cyclery and tell them what you are doing. They have what you need whether it is the spacer or new freehub and axle whichever you decide on. If your frame is steel go ahead and use the 8-9 body and spacer since that will be the least expensive option.

I have been through this both ways. Feel free to ask for more info if you need it.
Regards,
Raymond

Another/related question: Can I fit a 130mm 8-speed hub in my aluminum frame, 128mm rear dropouts?

I have a 1989 Cannondale frame, and I measure a rear drop-out spacing of 128mm. Is that possible? Was a 1989 Cannondale originally 130mm, but I've bent the aluminum by always running old school 6-speed freewheel wheels all the time? Now I'm thinking of switching to and 8-speed SIS system, that I gather is 130mm, I'm wondering what is possible. Thanks to any/all for your input!

I have a 1989 Cannondale frame, and I measure a rear drop-out spacing of 128mm. Is that possible? Was a 1989 Cannondale originally 130mm, but I've bent the aluminum by always running old school 6-speed freewheel wheels all the time?

The oddball 128 was due to Cannondale trying to please both ends of the spectrum. Lot of manufacturers were doing the samething in that time frame, knowing the standard was changing. You should be able to drop that 130mm in with no worries.

Another/related question: Can I fit a 130mm 8-speed hub in my aluminum frame, 128mm rear dropouts?

I have a 1989 Cannondale frame, and I measure a rear drop-out spacing of 128mm. Is that possible? Was a 1989 Cannondale originally 130mm, but I've bent the aluminum by always running old school 6-speed freewheel wheels all the time? Now I'm thinking of switching to and 8-speed SIS system, that I gather is 130mm, I'm wondering what is possible. Thanks to any/all for your input!
This post died tragically almost year and a half ago. Please let us just mourn it in peace. Check the last post dates people.

The oddball 128 was due to Cannondale trying to please both ends of the spectrum. Lot of manufacturers were doing the samething in that time frame, knowing the standard was changing. You should be able to drop that 130mm in with no worries.

Ah Ha!! Now that's an interesting piece of history there! Thank You, Dobber! :beer: